Re: [PATCH] hurd: '_hurd_raise_signal' checks signal number is valid

[Samuel Thibault <samuel.thibault@gnu.org>]

Hello,

Jessica Clarke, le mar. 13 oct. 2020 22:20:15 +0100, a ecrit:
> On 13 Oct 2020, at 22:16, Ludovic Courtès <ludo@gnu.org> wrote:
> > Previously, 'pthread_kill (pthread_self (), -1)' would wrongfully
> > succeed:
> > 
> >  https://lists.gnu.org/archive/html/guix-devel/2020-10/msg00152.html

> > --- a/hurd/hurd-raise.c
> > +++ b/hurd/hurd-raise.c
> > @@ -28,6 +28,9 @@ int
> > _hurd_raise_signal (struct hurd_sigstate *ss,
> > 		    int signo, const struct hurd_signal_detail *detail)
> > {
> > +  if (signo < 1 || signo >= _NSIG)
> > +    return EINVAL;
> > +
> 
> From pthread_kill(3):
> 
>     If sig is 0, then no signal is sent, but error checking is still performed.
> 
> I interpret that as meaning it validates thread but ignores sig.

__pthread_kill actually already check for sig == 0, _hurd_raise_signal
is really not supposed to be called with sig == 0.

But thanks for making sure we don't miss that case :)

Samuel